What is Usher Syndrome Type 3?
Usher syndrome type 3 is an inherited disease that causes progressive hearing loss and vision impairment. The rate at which hearing and vision decline varies greatly from person to person, even among those in the same family. In some people, the hearing and/or vision loss can be profound, while in others it can be milder.
People with Usher syndrome type 3 are born with normal hearing and most commonly develop hearing loss in their teenage years, requiring hearing aids by mid- to late-adulthood. By middle age, they are often completely deaf.
Usher syndrome type 3 causes an eye disease known as retinitis pigmentosa. Often arising during puberty, this causes night blindness that progresses to blind spots in the late teens or early adult years. Peripheral (side) vision is often the first to be reduced. Often by mid-life, the person is legally blind.
Unlike other forms of Usher syndrome, type 3 does not usually cause major problems with balance. Some problems may arise later in life, however.
The disease does not affect intelligence nor does it cause any other health problems.
How common is Usher Syndrome Type 3?
Usher syndrome type 3 is rare, making up just 2% of all cases of Usher syndrome. Type 3 is more common in Finland and among Ashkenazi Jews. One study showed that in the New York City area, 0.7% of Ashkenazi Jews are carriers of a particular mutation, which would mean that 1.2 in 100,000 Ashkenazi Jewish children would be affected.
How is Usher Syndrome Type 3 treated?
There is no cure for Usher syndrome, however there are ways to negotiate the vision and hearing loss it causes.
People with the disease will learn to speak normally before their hearing declines. They can explore a range of options including cochlear implants, hearing aids, or sign language.
A person with Usher syndrome will eventually require low vision aids and specialized instruction on how to cope with their limited vision. They can be prone to accidental injury due to their vision loss and may need to devise systems to avoid such problems.
Specialists in both hearing loss and vision loss can guide people to the best options to fit their needs.
What is the prognosis for a person with Usher Syndrome Type 3?
Usher syndrome type 3 will cause severe hearing and vision impairment by mid-life, however it does not affect one’s lifespan or intelligence.